1. FIELD OF THE INVENTION
The present invention relates to 3,4-dipivaloxy-.alpha.-[(isopropylamino)methyl]benzyl alcohol and its use in the treatment of glaucoma in warm-blooded animals, e.g., humans. More specifically, the present invention relates to the use of the above-mentioned compound in lowering intraocular pressure without initiating attendant cardiac excitatory activity.
2. DESCRIPTION OF THE PRIOR ART
Recently, the use of 3,4-dihydroxy-.alpha.-[(isopropylamino)methyl]benzyl alcohol (commonly known as "isoproterenol") in the treatment of glaucoma has been disclosed. See, Netherlands Patent 7,308,193.
Isoproterenol is a well-known sympathomimetic amine which acts almost exclusively on the .beta.-receptors of the postganglionic adrenergic nerves in the sympathetic nervous system and, therefore, the administration of isoproterenol generally produces, among other things, a cardiac excitatory action manifested by tachycardia, palpitation and an increase in the force of contraction of the heart muscle, dilation of vascular beds supplying skeletal muscle, and relaxation of bronchial muscle. As a consequence of the foregoing, while isoproterenol may adequately reduce intraocular pressure in a patient suffering from glaucoma, the inherent cardiac disadvantages associated with this compound as described earlier has substantially precluded its wide-spread acceptance as an antiglaucoma agent.
As one can appreciate, glaucoma is generally an illness of the elderly. Consequently, the fact that isoproterenol will accentuate cardiac action to such an extent that resultant tachycardia and palpitation become undesirable side effects precludes its use as an effective anti-glaucoma agent in a vast majority of patients.
Moreover, because isoproterenol is relatively lipophobic, it does not readily pass through the ophthalmic membrane (eye). As such, more of the compound is required to achieve a therapeutic effect but at the expense of great ophthalmic pain to the patient.
Finally, isoproterenol causes mydriasis (pupil enlargement) concurrently and/or subsequent to lowering intraocular pressure, which results in temporary vision impairment.
It is, therefore, obviously apparent that a need exists for a useful derivative of isoproterenol which possesses anti-glaucoma activity, while remaining essentially free from the unwanted cardiovascular disadvantages described above.